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<h3>
Ryan Scott pushed to branch wip/T17775
at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4>
Commits:
</h4>
<ul>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1f9db3e79bd0d70e5a1491174d540717f3bce2bf">1f9db3e7</a></strong>
<div>
<span>by Kirill Elagin</span>
<i>at 2020-03-12T09:45:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">pretty-printer: Properly parenthesise LastStmt
After ApplicatveDo strips the last `return` during renaming, the pretty
printer has to restore it. However, if the return was followed by `$`,
the dollar was stripped too and not restored.
For example, the last stamement in:
```
foo = do
x <- ...
...
return $ f x
```
would be printed as:
```
return f x
```
This commit preserved the dolar, so it becomes:
```
return $ f x
```
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5cb93af73499f9cee4a17427629840feb26171e5">5cb93af7</a></strong>
<div>
<span>by Kirill Elagin</span>
<i>at 2020-03-12T09:45:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">pretty-printer: Do not print ApplicativeDo join
* Do not print `join` in ApplictiveStmt, unless ppr-debug
* Print parens around multiple parallel binds
When ApplicativeDo is enabled, the renamer analyses the statements of a
`do` block and in certain cases marks them as needing to be rewritten
using `join`.
For example, if you have:
```
foo = do
a <- e1
b <- e2
doSomething a b
```
it will be desugared into:
```
foo = join (doSomething <$> e1 <*> e2)
```
After renaming but before desugaring the expression is stored
essentially as:
```
foo = do
[will need join] (a <- e1 | b <- e2)
[no return] doSomething a b
```
Before this change, the pretty printer would print a call to `join`,
even though it is not needed at this stage at all. The expression will be
actually rewritten into one using join only at desugaring, at which
point a literal call to join will be inserted.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3a259092a02e84d6b45da6b232cfc022898451a0">3a259092</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-12T09:46:29-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Expose compulsory unfoldings always
The unsafeCoerce# patch requires that unsafeCoerce# has
a compulsory unfolding that is always available. So we have
to be careful to expose compulsory unfoldings unconditionally
and consistently.
We didn't get this quite right: #17871. This patch fixes
it. No real surprises here.
See Note [Always expose compulsory unfoldings] in GHC.Iface.Tidy
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6a65b8c2f5b4bc7abdb0ca3b5876df694acb8194">6a65b8c2</a></strong>
<div>
<span>by Alp Mestanogullari</span>
<i>at 2020-03-13T02:29:20-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">hadrian: improve dependency tracking for the check-* programs
The code in Rules.Register responsible for finding all the build artifacts
that Cabal installs when registering a library (static/shared libs, .hi files,
...) was looking in the wrong place. This patch fixes that logic and makes sure
we gather all those artifacts in a list to declare that the rule for a given
`.conf` file, our proxy for "Hadrian, please install this package in the package
db for this stage", also produces those artifacts under the said package
database.
We also were completely missing some logic to declare that the check-* programs
have dependencies besides their source code, at least when testing an in-tree
compiler.
Finally, this patch also removes redundant packages from 'testsuitePackages',
since they should already be covered by the stage<N>Packages lists from
Settings.Default.
With this patch, after a complete build and freezing stage 1, a change to
`compiler/parser/Parser.y` results in rebuilding the ghc lib, reinstalling it,
and rebuilding the few programs that depend on it, _including_ `check-ppr` and
`check-api-annotations` (therefore fixing #17273).
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/44fad4a925c06fa2b14611ea08acea9210ee4e00">44fad4a9</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-13T02:30:22-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Rename isDllName
I wanted to fix the dangling comment in `isDllName` ("This is the cause
of #", #8696 is already mentioned earlier). I took the opportunity to
change the function name to better reflect what it does.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2f292db8f10134919c420b71b8a5eccd379212ad">2f292db8</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-13T02:31:03-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update documentation for closureSize
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f124ff0dfccced755ee97ecac027119269996f8f">f124ff0d</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-13T02:31:40-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Rework triggering of release builds
Use a push option instead of tagging.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7f25557a6f240943ebe3eb3b3c7178e76a3e93e1">7f25557a</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-13T10:38:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Distinguish integer-simple test envs
Previously two integer-simple jobs declared the same test environment. One (the nightly job) was built in the perf way, the other in the validate way. Consequently they had appreciably different performance characteristics, causing in the nightly job to spuriously fail with performance changes.</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c12a2ec5fe4e7f94d565c0e6398d1d79854db146">c12a2ec5</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-14T05:25:30-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix Lint
Ticket #17590 pointed out a bug in the way the linter dealt with
type lets, exposed by the new uniqAway story.
The fix is described in Note [Linting type lets]. I ended up
putting the in-scope Ids in a different env field, le_ids,
rather than (as before) sneaking them into the TCvSubst.
Surprisingly tiresome, but done.
Metric Decrease:
hie002
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b989845e378081f0932a7fec528e68daeeaa14fb">b989845e</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-14T05:26:11-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Hadrian: fix absolute buildroot support (#17822)
Shake's "**" wildcard doesn't match absolute root. We must use "//" instead.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4f117135673b36816c343bc11efcbb8396160c75">4f117135</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-14T05:26:49-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make: refactor GMP rules
Document and use simpler rules for the ghc-gmp.h header.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7432b327a3c43c4e2e7c777b41a8e17899b8d0d1">7432b327</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-14T05:27:28-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use correct option name (-opti) (fix #17314)
s/pgmo/opti
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8f7dd5710b80906ea7a3e15b7bb56a883a49fed8">8f7dd571</a></strong>
<div>
<span>by Judah Jacobson</span>
<i>at 2020-03-14T05:28:07-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Allow overriding LD_STAGE0 and AR_STAGE0 in the configure script.
Previously it was possible to override the stage0 C compiler via `CC_STAGE0`,
but you couldn't override `ld` or `ar` in stage0. This change allows overriding them
by setting `LD_STAGE0` or `AR_STAGE0`, respectively.
Our team uses this feature internally to take more control of our GHC build
and make it run more hermetically.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7c3e39a9a7ccb3b6c2953b0397a0d315dc0ec7d5">7c3e39a9</a></strong>
<div>
<span>by Judah Jacobson</span>
<i>at 2020-03-14T05:28:07-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use AC_ARG_VAR for LD_STAGE0 and AR_STAGE0.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/20d4d676964382b313b9e44062e45a7c38621999">20d4d676</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-14T05:28:43-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">nonmoving: Don't traverse filled segment list in pause
The non-moving collector would previously walk the entire filled segment
list during the preparatory pause. However, this is far more work than
is strictly necessary. We can rather get away with merely collecting the
allocators' filled segment list heads and process the lists themselves
during the concurrent phase. This can significantly reduce the maximum
gen1 GC pause time in programs with high rates of long-lived allocations.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/fdfa2d0121ca8cc22479dd17a74afa58fc2b39f5">fdfa2d01</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-14T05:29:18-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">nonmoving: Remove redundant bitmap clearing
nonmovingSweep already clears the bitmap in the sweep loop. There is no
reason to do so a second time.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2f8c77673f1faf0d8fed6df2bdd1ca15d696a010">2f8c7767</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-14T05:29:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simple refactor of cheapEqExpr
No change in functionality. Just seems tidier (and signficantly more
efficient) to deal with ticks directly than to call stripTicksTopE.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/88f7a76208b0fcf41ca0e16d18a71523f0601ee5">88f7a762</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-14T05:29:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Improve CSE.combineAlts
This patch improves the way that CSE combines identical
alternatives. See #17901.
I'm still not happy about the duplication between CSE.combineAlts
and GHC.Core.Utils.combineIdenticalAlts; see the Notes with those
functions. But this patch is a step forward.
Metric Decrease:
T12425
T5642
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8b95ddd3f20a67acf5251347d80f9cab191bdfc4">8b95ddd3</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-14T05:30:31-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Add integer-simple release build for Windows
Closes #16144.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e3c374cc5bd7eb49649b9f507f9f7740697e3f70">e3c374cc</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-14T05:31:07-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Wrap an implication around class-sig kind errors
Ticket #17841 showed that we can get a kind error
in a class signature, but lack an enclosing implication
that binds its skolems.
This patch
* Adds the wrapping implication: the new call to
checkTvConstraints in tcClassDecl1
* Simplifies the API to checkTvConstraints, which
was not otherwise called at all.
* Simplifies TcErrors.report_unsolved by *not*
initialising the TidyEnv from the typechecker lexical
envt. It's enough to do so from the free vars of the
unsolved constraints; and we get silly renamings if
we add variables twice: once from the lexical scope
and once from the implication constraint.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/73133a3b601b76c46098fb8ad3c76de5fe04c9b2">73133a3b</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-14T05:31:07-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Refactoring in TcSMonad
This patch is just refactoring: no change in
behaviour.
I removed the rather complicated
checkConstraintsTcS
checkTvConstraintsTcS
in favour of simpler functions
emitImplicationTcS
emitTvImplicationTcS
pushLevelNoWorkList
The last of these is a little strange, but overall
it's much better I think.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/93c88c266eacd80a7f2a1754778167390c287b18">93c88c26</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-14T05:31:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: Make `open` calls interruptible
As noted in #17912, `open` system calls were `safe` rather than
`interruptible`. Consequently, the program could not be interrupted with
SIGINT if stuck in a slow open operation. Fix this by marking
`c_safe_open` as interruptible.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bee4cdad4ce68a5bbe6af493d99f0197a34eef5c">bee4cdad</a></strong>
<div>
<span>by Vladislav Zavialov</span>
<i>at 2020-03-14T05:32:18-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove second tcLookupTcTyCon in tcDataDefn
Before this patch, tcDataDefn used to call tcLookupTcTyCon twice in a row:
1. in bindTyClTyVars itself
2. in the continuation passed to it
Now bindTyClTyVars passes the TcTyCon to the continuation, making
the second lookup unnecessary.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3f116d35a5b028ae2bb22da5063900d2f3d0b476">3f116d35</a></strong>
<div>
<span>by Cale Gibbard</span>
<i>at 2020-03-14T19:34:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Enable stage1 build of haddock
The submodule has already been bumped to contain the fix.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/49e9d7395a13584f15798bce1601b8d3a6633f11">49e9d739</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-14T19:35:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">rts: Fix printClosure when printing fwd ptrs
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1de3ab4a147eeb0b34b24a3c0e91f174e6e5cb79">1de3ab4a</a></strong>
<div>
<span>by Krzysztof Gogolewski</span>
<i>at 2020-03-14T19:36:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove unused field var_inline (#17915)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d30aeb4b38381758025bc1002eb2135ad6bc58b8">d30aeb4b</a></strong>
<div>
<span>by Krzysztof Gogolewski</span>
<i>at 2020-03-15T03:57:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Document restriction on SCC pragma syntax
Currently, the names of cost centres must be quoted or
be lowercase identifiers.
Fixes #17916.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b4774598e6bd060b1b4230b11b734ca40022980d">b4774598</a></strong>
<div>
<span>by Brian Foley</span>
<i>at 2020-03-15T03:58:18-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove some dead code
>From the notes.ghc.drop list found using weeder in #17713
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/dd6ffe6be742cf3ec98406704fef53ad86cc1560">dd6ffe6b</a></strong>
<div>
<span>by Viktor Dukhovni</span>
<i>at 2020-03-15T03:58:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Note platform-specific Foreign.C.Types in context
Also fix the markup in the general note at the top of the module. Haddock
(usability trade-off), does not support multi-line emphasised text.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2e82465fff5851f00449131fdc8bacd3ca95f90f">2e82465f</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-15T10:57:10-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Refactor CmmToAsm (disentangle DynFlags)
This patch disentangles a bit more DynFlags from the native code
generator (CmmToAsm).
In more details:
- add a new NCGConfig datatype in GHC.CmmToAsm.Config which contains the
configuration of a native code generation session
- explicitly pass NCGConfig/Platform arguments when necessary
- as a consequence `sdocWithPlatform` is gone and there are only a few
`sdocWithDynFlags` left
- remove the use of `unsafeGlobalDynFlags` from GHC.CmmToAsm.CFG
- remove `sdocDebugLevel` (now we pass the debug level via NCGConfig)
There are still some places where DynFlags is used, especially because
of pretty-printing (CLabel), because of Cmm helpers (such as
`cmmExprType`) and because of `Outputable` instance for the
instructions. These are left for future refactoring as this patch is
already big.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c35c545d3f32f092c52052349f741739a844ec0f">c35c545d</a></strong>
<div>
<span>by Judah Jacobson</span>
<i>at 2020-03-15T10:57:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add a -no-haddock flag.
This flag undoes the effect of a previous "-haddock" flag. Having both flags makes it easier
for build systems to enable Haddock parsing in a set of global flags, but then disable it locally for
specific targets (e.g., third-party packages whose comments don't pass the validation in the latest GHC).
I added the flag to expected-undocumented-flags.txt since `-haddock` was alreadyin that list.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cfcc3c9a1f2e4e33bed4c40767f8e7971e331c15">cfcc3c9a</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-15T10:58:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix global_link of TSOs for threads reachable via dead weaks
Fixes #17785
Here's how the problem occurs:
- In generation 0 we have a TSO that is finished (i.e. it has no more
work to do or it is killed).
- The TSO only becomes reachable after collectDeadWeakPtrs().
- After collectDeadWeakPtrs() we switch to WeakDone phase where we don't
move TSOs to different lists anymore (like the next gen's thread list
or the resurrected_threads list).
- So the TSO will never be moved to a generation's thread list, but it
will be promoted to generation 1.
- Generation 1 collected via mark-compact, and because the TSO is
reachable it is marked, and its `global_link` field, which is bogus at
this point (because the TSO is not in a list), will be threaded.
- Chaos ensues.
In other words, when these conditions hold:
- A TSO is reachable only after collectDeadWeakPtrs()
- It's finished (what_next is ThreadComplete or ThreadKilled)
- It's retained by mark-compact collector (moving collector doesn't
evacuate the global_list field)
We end up doing random mutations on the heap because the TSO's
global_list field is not valid, but it still looks like a heap pointer
so we thread it during compacting GC.
The fix is simple: when we traverse old_threads lists to resurrect
unreachable threads the threads that won't be resurrected currently
stays on the old_threads lists. Those threads will never be visited
again by MarkWeak so we now reset the global_list fields. This way
compacting GC does not thread pointers to nowhere.
Testing
-------
The reproducer in #17785 is quite large and hard to build, because of
the dependencies, so I'm not adding a regression test.
In my testing the reproducer would take a less than 5 seconds to run,
and once in every ~5 runs would fail with a segfault or an assertion
error. In other cases it also fails with a test failure. Because the
tests never fail with the bug fix, assuming the code is correct, this
also means that this bug can sometimes lead to incorrect runtime
results.
After the fix I was able to run the reproducer repeatedly for about an
hour, with no runtime crashes or test failures.
To run the reproducer clone the git repo:
$ git clone https://github.com/osa1/streamly --branch ghc-segfault
Then clone primitive and atomic-primops from their git repos and point
to the clones in cabal.project.local. The project should then be
buildable using GHC HEAD. Run the executable `properties` with `+RTS -c
-DZ`.
In addition to the reproducer above I run the test suite using:
$ make slowtest EXTRA_HC_OPTS="-debug -with-rtsopts=-DS \
-with-rtsopts=-c +RTS -c -RTS" SKIPWAY='nonmoving nonmoving_thr'
This enables compacting GC always in both GHC when building the test
programs and when running the test programs, and also enables sanity
checking when running the test programs. These set of flags are not
compatible for all tests so there are some failures, but I got the same
set of failures with this patch compared to GHC HEAD.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/818b3c38e7548f4720815f76969238d82c9650f7">818b3c38</a></strong>
<div>
<span>by Lysxia</span>
<i>at 2020-03-16T23:52:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: add strict IO functions: readFile', getContents', hGetContents'
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/18a346a4b5a02b8c62e8eedb91b35c2d8e754b96">18a346a4</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-16T23:53:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Core (#13009)
Update submodule: haddock
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/92327e3afd9d2650c9cc9610297d40c2712da085">92327e3a</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-16T23:54:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update sanity checking for TSOs:
- Remove an invalid assumption about GC checking what_next field. The GC
doesn't care about what_next at all, if a TSO is reachable then all
its pointers are followed (other than global_tso, which is only
followed by compacting GC).
- Remove checkSTACK in checkTSO: TSO stacks will be visited in
checkHeapChain, or checkLargeObjects etc.
- Add an assertion in checkTSO to check that the global_link field is
sane.
- Did some refactor to remove forward decls in checkGlobalTSOList and
added braces around single-statement if statements.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e1aa40525ddac370766907a49682976e2ea78422">e1aa4052</a></strong>
<div>
<span>by PHO</span>
<i>at 2020-03-17T07:36:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Don't use non-portable operator "==" in configure.ac
The test operator "==" is a Bash extension and produces a wrong result
if /bin/sh is not Bash.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/89f034ddeb4ad7d93c877d5bdbcf2cca7a44f79c">89f034dd</a></strong>
<div>
<span>by Maximilian Tagher</span>
<i>at 2020-03-17T07:36:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Document the units of -ddump-timings
Right now, in the output of -ddump-timings to a file, you can't tell what the units are:
```
CodeGen [TemplateTestImports]: alloc=22454880 time=14.597
```
I believe bytes/milliseconds are the correct units, but confirmation would be appreciated. I'm basing it off of this snippet from `withTiming'`:
```
when (verbosity dflags >= 2 && prtimings == PrintTimings)
$ liftIO $ logInfo dflags (defaultUserStyle dflags)
(text "!!!" <+> what <> colon <+> text "finished in"
<+> doublePrec 2 time
<+> text "milliseconds"
<> comma
<+> text "allocated"
<+> doublePrec 3 (realToFrac alloc / 1024 / 1024)
<+> text "megabytes")
```
which implies time is in milliseconds, and allocations in bytes (which divided by 1024 would be KB, and again would be MB)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/beffa14771ebd6ba24b20337f29045364621c5fa">beffa147</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-17T07:37:25-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Implement mapTyCo like foldTyCo
This patch makes mapType use the successful idiom described
in TyCoRep
Note [Specialising foldType]
I have not yet changed any functions to use mapType, though there
may be some suitable candidates.
This patch should be a no-op in terms of functionality but,
because it inlines the mapper itself, I'm hoping that there may
be some modest perf improvements.
Metric Decrease:
T5631
T5642
T3064
T9020
T14683
hie002
haddock.Cabal
haddock.base
haddock.compiler
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5800ebfeb2fe3e3ed985cdf08a66defea73db71d">5800ebfe</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-17T07:38:08-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Don't update ModDetails with CafInfos when opts are disabled
This is consistent with the interface file behavior where we omit
HsNoCafRefs annotations with -fomit-interface-pragmas (implied by -O0).
ModDetails and ModIface are just different representations of the same
thing, so they really need to be in sync. This patch does the right
thing and does not need too much explanation, but here's an example of a
problem not doing this causes in !2842:
-- MyInteger.hs
module MyInteger
( MyInteger (MyInteger)
, ToMyInteger (toMyInteger)
) where
newtype MyInteger = MyInteger Integer
class ToMyInteger a where
toMyInteger :: a -> MyInteger
instance ToMyInteger Integer where
toMyInteger = MyInteger {- . succ -}
-- Main.hs
module Main
( main
) where
import MyInteger (MyInteger (MyInteger), toMyInteger)
main :: IO ()
main = do
let (MyInteger i) = (id . toMyInteger) (41 :: Integer)
print i
If I build this with -O0, without this fix, we generate a ModDetails with
accurate LFInfo for toMyInteger (MyInteger.$fToMyIntegerInteger) which says that
it's a LFReEntrant with arity 1. This means in the use site (Main) we tag the
value:
R3 = MyInteger.$fToMyIntegerInteger_closure + 1;
R2 = GHC.Base.id_closure;
R1 = GHC.Base.._closure;
Sp = Sp - 16;
call stg_ap_ppp_fast(R4, R3, R2, R1) args: 24, res: 0, upd: 24;
Now we change the definition by uncommenting the `succ` part and it becomes a thunk:
MyInteger.$fToMyIntegerInteger [InlPrag=INLINE (sat-args=0)]
:: MyInteger.ToMyInteger GHC.Integer.Type.Integer
[GblId[DFunId(nt)]] =
{} \u [] $ctoMyInteger_rEA;
and its LFInfo is now LFThunk. This change in LFInfo makes a difference in the
use site: we can no longer tag it.
But becuase the interface fingerprint does not change (because ModIface does not
change) we don't rebuild Main and tag the thunk.
(1.2% increase in allocations when building T12545 on armv7 because we
generate more code without CafInfos)
Metric Increase:
T12545
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5b632dad2e1d373606fe29f7eee0daf15641560f">5b632dad</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add example for Data.Semigroup.diff
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4d85d68b004a3d577c0e27d9e6fdddd118e8a9f3">4d85d68b</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Clean up
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/75168d07c9c30289709423fc184bbab8dcad0f4e">75168d07</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make example collapsible
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/53ff2cd0c49735e8f709ac8a5ceab68483eb89df">53ff2cd0</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-17T13:46:57+00:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix #17021 by checking more return kinds
All the details are in new Note [Datatype return kinds] in
TcTyClsDecls.
Test case: typecheck/should_fail/T17021{,b}
typecheck/should_compile/T17021a
Updates haddock submodule
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/528df8ecb4e2f9c78b1ae4ab7ff8230644e9b643">528df8ec</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-18T10:06:43-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Core operations (#13009)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4e8a71c1138b587dfbab8a1823b3f7fa6f0166bd">4e8a71c1</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-18T10:07:19-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add release note about fix to #16502.
We thought we needed to update the manual, but the fix for #16502
actually brings the implementation in line with the manual. So we
just alert users of how to update their code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5cbf9934c59f7726781cc4cccf4748a5c09c4997">5cbf9934</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-19T00:39:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update "GHC differences to the FFI Chapter" in user guide.
The old entry had a heavy focus on how things had been. Which is
not what I generally look for in a user guide.
I also added a small section on behaviour of nested safe ffi calls.
[skip-ci]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b03fd3bcd4ff14aed2942275c3b0db5392dc913c">b03fd3bc</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-03-19T00:40:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">PmCheck: Use ConLikeSet to model negative info
In #17911, Simon recognised many warnings stemming from over-long list
unions while coverage checking Cabal's `LicenseId` module.
This patch introduces a new `PmAltConSet` type which uses a `UniqDSet`
instead of an association list for `ConLike`s. For `PmLit`s, it will
still use an assocation list, though, because a similar map data
structure would entail a lot of busy work.
Fixes #17911.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/64f207566931469648e791df4f0f0384d45cddd0">64f20756</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-19T12:16:49-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Refactoring: use Platform instead of DynFlags when possible
Metric Decrease:
ManyConstructors
T12707
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cb1785d9f839e34a3a4892f354f0c51cc6553c0e">cb1785d9</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-19T12:16:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">FastString: fix eager reading of string ptr in hashStr
This read causes NULL dereferencing when len is 0.
Fixes #17909
In the reproducer in #17909 this bug is triggered as follows:
- SimplOpt.dealWithStringLiteral is called with a single-char string
("=" in #17909)
- tailFS gets called on the FastString of the single-char string.
- tailFS checks the length of the string, which is 1, and calls
mkFastStringByteString on the tail of the ByteString, which is an
empty ByteString as the original ByteString has only one char.
- ByteString's unsafeUseAsCStringLen returns (NULL, 0) for the empty
ByteString, which is passed to mkFastStringWith.
- mkFastStringWith gets hash of the NULL pointer via hashStr, which
fails on empty strings because of this bug.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/73a7383ebc17f495d7acd04007c8c56b46532cb6">73a7383e</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-20T20:42:56-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simplify treatment of heterogeneous equality
Previously, if we had a [W] (a :: k1) ~ (rhs :: k2), we would
spit out a [D] k1 ~ k2 and part the W as irreducible, hoping for
a unification. But we needn't do this. Instead, we now spit out
a [W] co :: k2 ~ k1 and then use co to cast the rhs of the original
Wanted. This means that we retain the connection between the
spat-out constraint and the original.
The problem with this new approach is that we cannot use the
casted equality for substitution; it's too like wanteds-rewriting-
wanteds. So, we forbid CTyEqCans that mention coercion holes.
All the details are in Note [Equalities with incompatible kinds]
in TcCanonical.
There are a few knock-on effects, documented where they occur.
While debugging an error in this patch, Simon and I ran into
infelicities in how patterns and matches are printed; we made
small improvements.
This patch includes mitigations for #17828, which causes spurious
pattern-match warnings. When #17828 is fixed, these lines should
be removed.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/faa36e5b3674a7b2cfc6b931eec27b3558fad33b">faa36e5b</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-20T20:43:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Hadrian: ignore in-tree GMP objects with ``--lint``
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9a96ff6b1c19c9d0af9c9a39fb2c086f311c7239">9a96ff6b</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-20T20:44:17-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update core spec to reflect changes to Core.
Key changes:
* Adds a new rule for forall-coercions over coercion variables, which
was implemented but conspicuously missing from the spec.
* Adds treatment for FunCo.
* Adds treatment for ForAllTy over coercion variables.
* Improves commentary (including restoring a Note lost in
03d4852658e1b7407abb4da84b1b03bfa6f6db3b) in the source.
No changes to running code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7e0451c6ce78b08b5f7564aa03a9a86051b35163">7e0451c6</a></strong>
<div>
<span>by Sergej Jaskiewicz</span>
<i>at 2020-03-20T20:44:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix event message in withTiming'
This typo caused generating 'end' events without the corresponding 'begin' events.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1542a626a3649e5fc1becec1eff2715a6108d144">1542a626</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">fs.h: Add missing declarations on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3bcf2ccdd0bdd3cf176943ddb946e4fcef2ac7c1">3bcf2ccd</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump process submodule
Avoids redundant case alternative warning.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3b363ef9405c52369b63fc167ded8a533c6a5079">3b363ef9</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Normalize slashes in ghc-api annotations output
Enable `normalise_slashes` on `annotations`, `listcomps`, and
`parseTree` to fix Windows failures.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/25fc94295c68620c6928751aaadc46b11a185f0c">25fc9429</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Update expected output on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7f58ec6d94f49cf5713757710c6b80a682ee066b">7f58ec6d</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix TOP of T17786
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/aadcd909563d5ddf7b2fc469ee3c09c301b1a813">aadcd909</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Update expected output on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/dc1eb10dae03f3fe5f11de845c6772c229684c28">dc1eb10d</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">hadrian: Fix executable extension passed to testsuite driver
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/58f62e2caa19e13082807da1d49f94e9cf869322">58f62e2c</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Require that Windows-hadrian job passes
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8dd2415dd2f423688f33a8fb267857e3ff39754d">8dd2415d</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">hadrian: Eliminate redundant .exe from GHC path
Previously we were invoking:
bash -c
"c:/GitLabRunner/builds/eEQrxK4p/0/ghc/ghc/toolchain/bin/ghc.exe.exe
testsuite/mk/ghc-config.hs -o _build/test/bin/ghc-config.exe"
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/373621f61f812accdeba39c745eb7d015430ff8e">373621f6</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump hsc2hs submodule
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/abc02b4036c2d8efe50b720d8c8103c4f1b8899a">abc02b40</a></strong>
<div>
<span>by Hécate</span>
<i>at 2020-03-22T22:38:33-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Annotate the non-total function in Data.Foldable as such
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/19f125578247dfe8036b5793cb3f6b684474f9c7">19f12557</a></strong>
<div>
<span>by Josef Svenningsson</span>
<i>at 2020-03-23T14:05:33-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix ApplicativeDo regression #17835
A previous fix for #15344 made sure that monadic 'fail' is used properly
when translating ApplicativeDo. However, it didn't properly account
for when a 'fail' will be inserted which resulted in some programs
failing with a type error.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2643ba465cd2a133b6f495f34fc59cd1a6d23525">2643ba46</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-24T08:31:32-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add example and doc for Arg (Fixes #17153)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/703221f408b023a1b3433938572e7b5c24b4af60">703221f4</a></strong>
<div>
<span>by Roland Senn</span>
<i>at 2020-03-25T14:45:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use export list of Main module in function TcRnDriver.hs:check_main (Fix #16453)
- Provide the export list of the `Main` module as parameter to the
`compiler/typecheck/TcRnDriver.hs:check_main` function.
- Instead of `lookupOccRn_maybe` call the function `lookupInfoOccRn`.
It returns the list `mains_all` of all the main functions in scope.
- Select from this list `mains_all` all `main` functions that are in
the export list of the `Main` module.
- If this new list contains exactly one single `main` function, then
typechecking continues.
- Otherwise issue an appropriate error message.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3e27205a66b06a4501d87eb31e285eadbc693eb7">3e27205a</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-03-25T14:45:40-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove -fkill-absence and -fkill-one-shot flags
They seem to be a benchmarking vestige of the Cardinality paper and
probably shouldn't have been merged to HEAD in the first place.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/262e42aa34c4d5705c8d011907c351497dd4e862">262e42aa</a></strong>
<div>
<span>by Peter Trommler</span>
<i>at 2020-03-25T22:41:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Do not panic on linker errors
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0de03cd78729dc58a846c64b645e71057ec5d24e">0de03cd7</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-25T22:42:02-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">DynFlags refactoring III
Use Platform instead of DynFlags when possible:
* `tARGET_MIN_INT` et al. replaced with `platformMinInt` et al.
* no more DynFlags in PreRules: added a new `RuleOpts` datatype
* don't use `wORD_SIZE` in the compiler
* make `wordAlignment` use `Platform`
* make `dOUBLE_SIZE` a constant
Metric Decrease:
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7a04920b23376b2759b5049820400ddd40f7b89e">7a04920b</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: fix a typo in liftA doc
This change removes an extra '|' that should not be rendered in
the liftA documentation.
Tracking: #17929
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c5a15f7d257d0a2ded4850e38b6174965a7735b">1c5a15f7</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: add Control.Applicative optional example
This change adds an optional example.
Tracking: #17929
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6d172e63f3dd3590b0a57371efb8f924f1fcdf05">6d172e63</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: add markup around Except
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/eb2162c81964b3a1057c21c73574cc2b542d863a">eb2162c8</a></strong>
<div>
<span>by John Ericson</span>
<i>at 2020-03-26T12:37:08-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove unused `ghciTablesNextToCode` from compiler proper
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f51efc4bf5f20d1df3d11a2bb4c147f416367ae4">f51efc4b</a></strong>
<div>
<span>by Joachim Breitner</span>
<i>at 2020-03-26T12:37:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Prepare to use run-time tablesNextToCode in compiler exclusively
Factor out CPP as much as possible to prepare for runtime
determinattion.
Progress towards #15548
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c446220250dcada51d4bb33a0cc7d8ce572e8b6">1c446220</a></strong>
<div>
<span>by Joachim Breitner</span>
<i>at 2020-03-26T12:37:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use run-time tablesNextToCode in compiler exclusively (#15548)
Summary:
- There is no more use of the TABLES_NEXT_TO_CODE CPP macro in
`compiler/`. GHCI_TABLES_NEXT_TO_CODE is also removed entirely.
The field within `PlatformMisc` within `DynFlags` is used instead.
- The field is still not exposed as a CLI flag. We might consider some
way to ensure the right RTS / libraries are used before doing that.
Original reviewers:
Original subscribers: TerrorJack, rwbarton, carter
Original Differential Revision: https://phabricator.haskell.org/D5082
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1941ef4f050c0dfcb68229641fcbbde3a10f1072">1941ef4f</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Types (#13009)
Update Haddock submodule
Metric Increase:
haddock.compiler
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c7c6f1afc8e7f7ba5d256780bc9d5bb5f3e7601">1c7c6f1a</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove GHC.Types.Unique.Map module
This module isn't used anywhere in GHC.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f1a6c73d01912b389e012a0af81a5c2002e82636">f1a6c73d</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Merge GHC.Types.CostCentre.Init into GHC.Driver.CodeOutput
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/54250f2d8de910b094070c1b48f086030df634b1">54250f2d</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-29T17:29:30-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Demand analysis: simplify the demand for a RHS
Ticket #17932 showed that we were using a stupid demand for the RHS
of a let-binding, when the result is a product. This was the result
of a "fix" in 2013, which (happily) turns out to no longer be
necessary.
So I just deleted the code, which simplifies the demand analyser,
and fixes #17932. That in turn uncovered that the anticipation
of worker/wrapper in CPR analysis was inaccurate, hence the logic
that decides whether to unbox an argument in WW was extracted into
a function `wantToUnbox`, now consulted by CPR analysis.
I tried nofib, and got 0.0% perf changes.
All this came up when messing about with !2873 (ticket #17917),
but is idependent of it.
Unfortunately, this patch regresses #4267 and realised that it is now
blocked on #16335.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/03060b2f963436dd22582f3a1c218b7a74d302ec">03060b2f</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix T17786 on Windows
Fixes line ending normalization issue.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1f7995baaaf4dcba9b3abaddcd571ac66675ab19">1f7995ba</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix T17786
Fix missing quoting and expected exit code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ef9c608eba417c59fe45c9edd6a946c59f50b5d2">ef9c608e</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Mark T12971 as broken on Windows
Due to #17945.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e54500c12de051cb9695728d27c812e5160593ee">e54500c1</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:30:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Store ComponentId details
As far as GHC is concerned, installed package components ("units") are
identified by an opaque ComponentId string provided by Cabal. But we
don't want to display it to users (as it contains a hash) so GHC queries
the database to retrieve some infos about the original source package
(name, version, component name).
This patch caches these infos in the ComponentId itself so that we don't
need to provide DynFlags (which contains installed package informations)
to print a ComponentId.
In the future we want GHC to support several independent package states
(e.g. for plugins and for target code), hence we need to avoid
implicitly querying a single global package state.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7e7cb714173652165b8372c3450f4ccd6a377497">7e7cb714</a></strong>
<div>
<span>by Marius Bakke</span>
<i>at 2020-03-29T17:31:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Remove test that dlopens a PIE object.
glibc 2.30 disallowed dlopening PIE objects, so just remove the test.
Fixes #17952.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6c8f80d8876965539571d37d3c7f0fee43c300d2">6c8f80d8</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-29T17:32:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Correct haddocks for testBit in Data.Bits
It conflated the nth bit with the bit at offset n.
Now we instead give the definition in terms of `bit and `.&.`
on top of clearer phrasing.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c916f190b455d9c43459f81c7ee06d06ab3db957">c916f190</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-29T17:32:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Apply suggestion to libraries/base/Data/Bits.hs</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/64bf7f51064dad9c63728ac8bccdb9cf00bdb420">64bf7f51</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:32:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Add FreeBSD release job
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a0d8e92e9c9b67426aa139d6bc46363d8940f992">a0d8e92e</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-29T17:33:20-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Run checkNewDataCon before constraint-solving newtype constructors
Within `checkValidDataCon`, we used to run `checkValidType` on the
argument types of a newtype constructor before running
`checkNewDataCon`, which ensures that the user does not attempt
non-sensical things such as newtypes with multiple arguments or
constraints. This works out in most situations, but this falls over
on a corner case revealed in #17955:
```hs
newtype T = Coercible () T => T ()
```
`checkValidType`, among other things, peforms an ambiguity check on
the context of a data constructor, and that it turn invokes the
constraint solver. It turns out that there is a special case in the
constraint solver for representational equalities (read: `Coercible`
constraints) that causes newtypes to be unwrapped (see
`Note [Unwrap newtypes first]` in `TcCanonical`). This special case
does not know how to cope with an ill formed newtype like `T`, so
it ends up panicking.
The solution is surprisingly simple: just invoke `checkNewDataCon`
before `checkValidType` to ensure that the illicit newtype
constructor context is detected before the constraint solver can
run amok with it.
Fixes #17955.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/45eb9d8cad254440eaea25676d6788ca13baa2fb">45eb9d8c</a></strong>
<div>
<span>by Krzysztof Gogolewski</span>
<i>at 2020-03-29T17:33:59-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Minor cleanup
- Simplify mkBuildExpr, the function newTyVars was called
only on a one-element list.
- TTG: use noExtCon in more places. This is more future-proof.
- In zonkExpr, panic instead of printing a warning.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f024b6e385bd1448968b7bf20de05f655c815bae">f024b6e3</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-30T12:48:39+02:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Expect T4267 to pass
Since 54250f2d8de910b094070c1b48f086030df634b1 we expected T4267 to
fail, but it passes on CI.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/57b888c0e90be7189285a6b078c30b26d0923809">57b888c0</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-31T10:54:20-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Require GHC 8.8 as the minimum compiler for bootstrapping
This allows us to remove several bits of CPP that are either always
true or no longer reachable. As an added bonus, we no longer need to
worry about importing `Control.Monad.Fail.fail` qualified to avoid
clashing with `Control.Monad.fail`, since the latter is now the same
as the former.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/33f095511a8fce4c945bbcd4feb3910c854dcb61">33f09551</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-31T10:54:57-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add regression test for #17963
The panic in #17963 happened to be fixed by commit
e3c374cc5bd7eb49649b9f507f9f7740697e3f70. This patch adds a
regression test to ensure that it remains fixed.
Fixes #17963.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/09a36e80ecaefcfb60eccda98bd06461d0aeca70">09a36e80</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-31T10:55:37-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simplify stderrSupportsAnsiColors
The combinator andM is used only once, and the code is shorter and
simpler if you inline it.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/95bccdd034ce4dd2d1bc36db9f1ba5e172550249">95bccdd0</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-31T10:56:19-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: Ensure that encoding global variables aren't inlined
As noted in #17970, these (e.g. `getFileSystemEncoding` and
`setFileSystemEncoding`) previously had unfoldings, which would
break their global-ness.
While not strictly necessary, I also add a NOINLINE on
`initLocaleEncoding` since it is used in `System.IO`, ensuring that we
only system's query the locale encoding once.
Fixes #17970.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/982aaa837aed564ae9b418cda8e97d4facff8fb8">982aaa83</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-31T10:56:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update hadrian index revision.
Required in order to build hadrian using ghc-8.10
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4b9c586472bf99425f7bbcf346472d7c54f05028">4b9c5864</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-31T10:57:32-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">integer-gmp: Bump version and add changelog entry
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9b39f2e6f63ae50cedd96eaf49146de8ed00fbc8">9b39f2e6</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-01T01:20:00-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Clean up "Eta reduction for data families" Notes
Before, there were two distinct Notes named
"Eta reduction for data families". This renames one of them to
"Implementing eta reduction for data families" to disambiguate the
two and fixes references in other parts of the codebase to ensure
that they are pointing to the right place.
Fixes #17313.
[ci skip]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7627eab5dd882eb6f1567e3ae95c6c770830a5eb">7627eab5</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-01T01:20:38-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix the changelog/@since information for hGetContents'/getContents'/readFile'
Fixes #17979.
[ci skip]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0002db1bf436cbd32f97b659a52b1eee4e8b21db">0002db1b</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-01T01:21:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Kill wORDS_BIGENDIAN and replace it with platformByteOrder (#17957)
Metric Decrease:
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7b21717907a741b56513f5e1fa1ebceecf971613">7b217179</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-04-01T15:03:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">PmCheck: Adjust recursion depth for inhabitation test
In #17977, we ran into the reduction depth limit of the typechecker.
That was only a symptom of a much broader issue: The recursion depth
of the coverage checker for trying to instantiate strict fields in the
`nonVoid` test was far too high (100, the `defaultMaxTcBound`).
As a result, we were performing quite poorly on `T17977`.
Short of a proper termination analysis to prove emptyness of a type,
we just arbitrarily default to a much lower recursion limit of 3.
Fixes #17977.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3c09f636a459f50119bfbb5bf798b9a9e19eb464">3c09f636</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-04-01T15:03:59-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make hadrian pass on the no-colour setting to GHC.
Fixes #17983.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b943b25d0786da64031ac63ddf9b4574182057bb">b943b25d</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-02T01:45:58-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Re-engineer the binder-swap transformation
The binder-swap transformation is implemented by the occurrence
analyser -- see Note [Binder swap] in OccurAnal. However it had
a very nasty corner in it, for the case where the case scrutinee
was a GlobalId. This led to trouble and hacks, and ultimately
to #16296.
This patch re-engineers how the occurrence analyser implements
the binder-swap, by actually carrying out a substitution rather
than by adding a let-binding. It's all described in
Note [The binder-swap substitution].
I did a few other things along the way
* Fix a bug in StgCse, which could allow a loop breaker to be CSE'd
away. See Note [Care with loop breakers] in StgCse. I think it can
only show up if occurrence analyser sets up bad loop breakers, but
still.
* Better commenting in SimplUtils.prepareAlts
* A little refactoring in CoreUnfold; nothing significant
e.g. rename CoreUnfold.mkTopUnfolding to mkFinalUnfolding
* Renamed CoreSyn.isFragileUnfolding to hasCoreUnfolding
* Move mkRuleInfo to CoreFVs
We observed respectively 4.6% and 5.9% allocation decreases for the following
tests:
Metric Decrease:
T9961
haddock.base
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/42d68364f66846969edf029f878875c10cdfe0b2">42d68364</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-04-02T01:46:34-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Preserve precise exceptions in strictness analysis
Fix #13380 and #17676 by
1. Changing `raiseIO#` to have `topDiv` instead of `botDiv`
2. Give it special treatment in `Simplifier.Util.mkArgInfo`, treating it
as if it still had `botDiv`, to recover dead code elimination.
This is the first commit of the plan outlined in
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/2525#note_260886.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0a88dd11594b8d8fd20500d026e657a5f99dfdd2">0a88dd11</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-04-02T01:47:25-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix a pointer format string in RTS
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5beac042b995b055a66bc16be536d9e920f6864d">5beac042</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-04-02T01:48:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove unused closure stg_IND_direct
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/88f38b03025386f0f1e8f5861eed67d80495168a">88f38b03</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-04-02T01:48:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Session: Memoize stderrSupportsAnsiColors
Not only is this a reasonable efficiency measure but it avoids making
reentrant calls into ncurses, which is not thread-safe. See #17922.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/27740f24cb70fc14b00c1212c06642a144a6117d">27740f24</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-02T01:49:21-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make Hadrian build with Cabal-3.2
GHC 8.10 ships with `Cabal-3.2.0.0`, so it would be convenient to
make Hadrian supporting building against 3.2.* instead of having to
rebuild the entirety of `Cabal-3.0.0.0`. There is one API change in
`Cabal-3.2.*` that affects Hadrian: the `synopsis` and `description`
functions now return `ShortText` instead of `String`. Since Hadrian
manipulates these `String`s in various places, I found that the
simplest fix was to use CPP to convert `ShortText` to `String`s
where appropriate.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4980200255dabf59ae537f10c55d19ef1a00bbdd">49802002</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-02T01:50:00-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update Stack resolver for hadrian/build-stack
Broken by 57b888c0e90be7189285a6b078c30b26d0923809
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/30a63e79c65b023497af4fe2347149382c71829d">30a63e79</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-02T01:50:36-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix two ASSERT buglets in reifyDataCon
Two `ASSERT`s in `reifyDataCon` were always using `arg_tys`, but
`arg_tys` is not meaningful for GADT constructors. In fact, it's
worse than non-meaningful, since using `arg_tys` when reifying a
GADT constructor can lead to failed `ASSERT`ions, as #17305
demonstrates.
This patch applies the simplest possible fix to the immediate
problem. The `ASSERT`s now use `r_arg_tys` instead of `arg_tys`, as
the former makes sure to give something meaningful for GADT
constructors. This makes the panic go away at the very least. There
is still an underlying issue with the way the internals of
`reifyDataCon` work, as described in
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227023, but we
leave that as future work, since fixing the underlying issue is
much trickier (see
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227087).
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ef7576c40f8de391ed8b1c81c38156202e6d17cf">ef7576c4</a></strong>
<div>
<span>by Zubin Duggal</span>
<i>at 2020-04-03T06:24:56-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add outputable instances for the types in GHC.Iface.Ext.Types, add -ddump-hie
flag to dump pretty printed contents of the .hie file
Metric Increase:
hie002
Because of the regression on i386:
compile_time/bytes allocated increased from i386-linux-deb9 baseline @ HEAD~10:
Expected hie002 (normal) compile_time/bytes allocated: 583014888.0 +/-10%
Lower bound hie002 (normal) compile_time/bytes allocated: 524713399
Upper bound hie002 (normal) compile_time/bytes allocated: 641316377
Actual hie002 (normal) compile_time/bytes allocated: 877986292
Deviation hie002 (normal) compile_time/bytes allocated: 50.6 %
*** unexpected stat test failure for hie002(normal)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9462452a4843a2c42fe055a0a7e274d5164d1dc0">9462452a</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-04-03T06:25:33-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Improve and refactor StgToCmm codegen for DataCons.
We now differentiate three cases of constructor bindings:
1)Bindings which we can "replace" with a reference to
an existing closure. Reference the replacement closure
when accessing the binding.
2)Bindings which we can "replace" as above. But we still
generate a closure which will be referenced by modules
importing this binding.
3)For any other binding generate a closure. Then reference
it.
Before this patch 1) did only apply to local bindings and we
didn't do 2) at all.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a214d2142c1bafa71fe52cb3823351ff9322d336">a214d214</a></strong>
<div>
<span>by Moritz Bruder</span>
<i>at 2020-04-03T06:26:11-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add singleton to NonEmpty in libraries/base
This adds a definition to construct a singleton non-empty list
(Data.List.NonEmpty) according to issue #17851.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f7597aa0c028ced898ac97e344754dd961b70c57">f7597aa0</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-03T06:26:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Testsuite: measure compiler stats for T16190
We were mistakenly measuring program stats
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a485c3c4049fff09e989bfd7d2ba47035c92a69b">a485c3c4</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-03T06:26:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Move blob handling into StgToCmm
Move handling of big literal strings from CmmToAsm to StgToCmm. It
avoids the use of `sdocWithDynFlags` (cf #10143). We might need to move
this handling even higher in the pipeline in the future (cf #17960):
this patch will make it easier.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cc2918a0407e1581e824ebd90a1fcbb0637d5744">cc2918a0</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-03T06:26:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Refactor CmmStatics
In !2959 we noticed that there was some redundant code (in GHC.Cmm.Utils
and GHC.Cmm.StgToCmm.Utils) used to deal with `CmmStatics` datatype
(before SRT generation) and `RawCmmStatics` datatype (after SRT
generation).
This patch removes this redundant code by using a single GADT for
(Raw)CmmStatics.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9e60273db47364fc08aeb5a389caf67559e0d353">9e60273d</a></strong>
<div>
<span>by Maxim Koltsov</span>
<i>at 2020-04-03T06:27:32-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix haddock formatting in Control.Monad.ST.Lazy.Imp.hs
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1b7e8a94cb3334fc0e513dec2db323f32c3a0713">1b7e8a94</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-04-03T06:28:08-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Turn newlines into spaces for hadrian/ghci.
The newlines break the command on windows.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4291bddaea3148908c55f235ee8978e1d9aa6f20">4291bdda</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-03T06:28:44-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Major improvements to the specialiser
This patch is joint work of Alexis King and Simon PJ. It does some
significant refactoring of the type-class specialiser. Main highlights:
* We can specialise functions with types like
f :: Eq a => a -> Ord b => b => blah
where the classes aren't all at the front (#16473). Here we can
correctly specialise 'f' based on a call like
f @Int @Bool dEqInt x dOrdBool
This change really happened in an earlier patch
commit 2d0cf6252957b8980d89481ecd0b79891da4b14b
Author: Sandy Maguire <sandy@sandymaguire.me>
Date: Thu May 16 12:12:10 2019 -0400
work that this new patch builds directly on that work, and refactors
it a bit.
* We can specialise functions with implicit parameters (#17930)
g :: (?foo :: Bool, Show a) => a -> String
Previously we could not, but now they behave just like a non-class
argument as in 'f' above.
* We can specialise under-saturated calls, where some (but not all of
the dictionary arguments are provided (#17966). For example, we can
specialise the above 'f' based on a call
map (f @Int dEqInt) xs
even though we don't (and can't) give Ord dictionary.
This may sound exotic, but #17966 is a program from the wild, and
showed significant perf loss for functions like f, if you need
saturation of all dictionaries.
* We fix a buglet in which a floated dictionary had a bogus demand
(#17810), by using zapIdDemandInfo in the NonRec case of specBind.
* A tiny side benefit: we can drop dead arguments to specialised
functions; see Note [Drop dead args from specialisations]
* Fixed a bug in deciding what dictionaries are "interesting"; see
Note [Keep the old dictionaries interesting]
This is all achieved by by building on Sandy Macguire's work in
defining SpecArg, which mkCallUDs uses to describe the arguments of
the call. Main changes:
* Main work is in specHeader, which marched down the [InBndr] from the
function definition and the [SpecArg] from the call site, together.
* specCalls no longer has an arity check; the entire mechanism now
handles unders-saturated calls fine.
* mkCallUDs decides on an argument-by-argument basis whether to
specialise a particular dictionary argument; this is new.
See mk_spec_arg in mkCallUDs.
It looks as if there are many more lines of code, but I think that
all the extra lines are comments!
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/40a85563a46c682eaab5fdf970f7c46afca78cb3">40a85563</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-04-03T18:26:19+03:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Revert accidental change in 9462452
[ci skip]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bd75e5da0f1f05f107325733b570bf28b379d2f2">bd75e5da</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-04T07:07:58-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Enable ImpredicativeTypes internally when typechecking selector bindings
This is necessary for certain record selectors with higher-rank
types, such as the examples in #18005. See
`Note [Impredicative record selectors]` in `TcTyDecls`.
Fixes #18005.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0333de05bfd9d4c81c3ac3a3390bcd2a3da7683e">0333de05</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-04T09:57:10-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simplify subsumption
This patch implements GHC Proposal 287: Simplify subsumption
and ticket #17775.
The highlights are:
* No deeplyInstantiate or deeplySkolemise
* No tcSubTypeDS
Everything else is a knock-on effect.
I did a bit of renaming to make things consistent
* tcPolyExpr becomes tcCheckPolyExpr
ditto tcPolyExprNC
* Add new function
tcCheckMonoExpr e ty = tcMon0Expr expr (mkCheckExpType ty)
and use it
This all comopiles, but needs some eta-expansion in haskeline, and
doubtless other packages.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bb6f1d60dc290f5cc2c2cc5d64a07db0ab53aab2">bb6f1d60</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-04T09:58:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Further refactoring and simplification
Reviewed the main changes with Richard
I had to do eta-expansion in a number of tests:
T10283
T10390
T14488
T1634
T4284
T9569a
T9834
tc145
tc160
tc208
tc210
twins
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2d0b2564fba58103466fc9d1681039bcfe4ccadb">2d0b2564</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-04-04T09:58:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump haskeline submodule
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/79e33feba7495de4b6d244e796ca0b04f9044588">79e33feb</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-04T09:58:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Delete commented-out code
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bff73ead58f886a5825a027298391b1a8c52ad91">bff73ead</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-04T09:58:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix (breaking) typo
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/049a44c8fcee7acd7e8b737147d47a03b95900ec">049a44c8</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-04T10:00:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Improve decomposition for FunTys
This just improves error messages, avoiding
Couldn't match type ‘Char’ with ‘Show a -> Char’
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bd8eda7c22e8ccf88c2bf30de3edb69ba5519e2c">bd8eda7c</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-04T10:00:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump Cabal submodule
As well as some miscellaneous fixes needed to make GHC itself
compile under simplified subsumption.
</pre>
</li>
</ul>
<h4>30 changed files:</h4>
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<a href="#587d266bb27a4dc3022bbed44dfa19849df3044c">
.gitlab-ci.yml
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compiler/GHC.hs
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compiler/GHC/ByteCode/Asm.hs
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compiler/GHC/ByteCode/InfoTable.hs
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compiler/GHC/ByteCode/Instr.hs
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compiler/GHC/ByteCode/Linker.hs
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compiler/GHC/Cmm.hs
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compiler/GHC/Cmm/BlockId.hs
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compiler/GHC/Cmm/Parser.y
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compiler/GHC/Cmm/Pipeline.hs
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<h5>The diff was not included because it is too large.</h5>
</div>
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